| 摘要 |
<p>A power supply apparatus (1) for powering a device includes a transformer (11) having a primary side (7), a secondary side (9) that is galvincally isolated from the primary side, a controller (13) for controlling the power supply apparatus, and a primary side auxiliary power feed (16) for facilitating start-up of the controller during a start-up phase of operation of a controller. The apparatus includes an element (17, 19) operable to interact with the primary side. The element is powered by the auxiliary power feed. Element control means (21), comprising delay function (23) and controlled switch (25), controls when the element is powered by the auxiliary power feed. The element control means determines the end of the start-up phase of operation of the controller, and only after this time closes the controlled switch in order to allow power from the auxiliary power feed to be applied to the element. The element may be the coil (19) of a relay (17) which controls whether or not the switched mains power supply (5) is interrupted or not.</p> |
